The present disclosure relates to an actuator, a touch panel display device, and an electronic apparatus.
Among portable electronic apparatuses, there is an electronic apparatuses provided with a speaker that generates sound (operation sound), such as beep sound, or a vibration generator that vibrates a case of the electronic apparatus.
In the related art, since the speaker and the vibration generator are provided separately, they occupy space within the case of the electronic apparatus, which is disadvantageous to miniaturization.
Therefore, Japanese Utility Model No. 2570923 suggests an actuator that has both a function as the speaker and a function as the diaphragm.
This actuator includes a diaphragm, a housing to which the diaphragm is attached, a coil attached to the diaphragm, a magnet disposed inside the coil, a spring that movably supports the magnet, and a plurality of members (yoke members) that constitute a magnetic circuit that leads lines of magnetic force from the magnet to the coil, and a case that is made of synthetic resin to accommodate the coil, the magnet, the spring, and the yoke. Here, the actuator is configured such that, when an electrical signal is supplied to the coil, the coil and the magnet are caused to relatively move, thereby vibrating the diaphragm to generate sound, and the vibration of the magnet vibrate the housing.
Meanwhile, in a touch panel display device to be used as an input device or an output device, its input screen can be configured freely by software. Therefore, the touch panel display device has flexibility that cannot be obtained from an input device that is configured using mechanical switches, and has many advantages that it can be made lightweight and compact, and the frequency of occurrence of mechanical failures is low. Thus, the touch panel display device is currently used in a wide range of operation panels of a variety of relatively large machines to input/output devices of very small portable apparatuses.
Since many touch panel display devices are operated simply by touching a flat and smooth panel surface with a finger of a user who operates the touch panel display devices, there does not exist feedback to the user caused from a sense of touch of a user's finger tip, such as click feeling that the user feels with his/her finger tip when an input device that is configured using mechanical switches is operated. This makes operational feeling unreliable. In order to improve this, JP-A-2003-288168 discloses a touch panel display device that is adapted to feed a sense of touch back to a finger tip of a user who operates the device.
The touch panel display device disclosed in this publication is adapted to vibrate a touch panel to be touched by a user's finger tip in a direction vertical to a panel surface of the touch panel, thereby generating a sense of touch in the user's finger tip.
Accordingly, if the above actuator is applied to the above touch panel display device, a sense of touch can be generated in an operating user's finger tip, and a sound, such as an operation sound, can also be generated.
Meanwhile, in the above-described known actuator, vibration of the magnet causes vibration of the housing. Therefore, as the weight of the magnet increases, greater vibration is generated.
However, if the actuator is intended to be miniaturized, the volume of the magnet is also miniaturized and thereby the magnet becomes lightweight. Therefore, it is disadvantageous to ensure the magnitude of vibration.
Moreover, in the above-described known actuator, the coil, the magnet, the spring, and the plurality of yoke members are incorporated into the case made of synthetic resin. Therefore, the number of parts increases and the assembling is complicated, which is disadvantageous to realize miniaturization and cost reduction.
Accordingly, it is desirable to provide an actuator, a touch panel display device, and an electronic apparatus that are advantageous to ensure the magnitude of vibration to be generated while realizing miniaturization.
It is also desirable to provide an actuator that is advantageous to realize miniaturization and cost reduction.
It is also desirable to provide a touch panel display device and an electronic apparatus that can generate a sense of touch in an operating user's finger tip and generate sound, and that are advantageous to realize cost reduction and miniaturization.